Biosludge is a semi-solid slurry producible from processing in a sewage treatment system in a waste water treatment plant. The biosludge generally includes microorganisms, microorganism metabolites, and organic or inorganic substances present in the sewage.
Referring to FIG. 1, a conventional method for disposing a biosludge includes a water removing step 11, a drying step 12, and a settling step 13. In the water removing step 11, a polymer flocculant is added to the biosludge to form flocs, followed by removing water from the biosludge by centrifuging or filtering to form a biosludge cake. In the drying step 12, the biosludge cake is baked to further reduce the water content thereof. Finally, in the settling step 13, the baked biosludge cake is landfilled or incinerated.
Besides, reduction of the biosludge with an ozone treatment is also proposed. However, for decreasing the cost for treatment of the biosludge and for reducing environmental pollution and release of carbon dioxide resulted from incineration, there is room for improving the efficiency in biosludge reduction.